// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/supports_user_data.h" #include "base/sequence_checker.h" namespace base { std::unique_ptr SupportsUserData::Data::Clone() { return nullptr; } SupportsUserData::SupportsUserData() { // Harmless to construct on a different execution sequence to subsequent // usage. DETACH_FROM_SEQUENCE(sequence_checker_); } SupportsUserData::SupportsUserData(SupportsUserData&&) = default; SupportsUserData& SupportsUserData::operator=(SupportsUserData&&) = default; SupportsUserData::Data* SupportsUserData::GetUserData(const void* key) const { DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); // Avoid null keys; they are too vulnerable to collision. DCHECK(key); auto found = user_data_.find(key); if (found != user_data_.end()) return found->second.get(); return nullptr; } void SupportsUserData::SetUserData(const void* key, std::unique_ptr data) { DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); // Avoid null keys; they are too vulnerable to collision. DCHECK(key); if (data.get()) user_data_[key] = std::move(data); else RemoveUserData(key); } void SupportsUserData::RemoveUserData(const void* key) { DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); user_data_.erase(key); } void SupportsUserData::DetachFromSequence() { DETACH_FROM_SEQUENCE(sequence_checker_); } void SupportsUserData::CloneDataFrom(const SupportsUserData& other) { for (const auto& data_pair : other.user_data_) { auto cloned_data = data_pair.second->Clone(); if (cloned_data) SetUserData(data_pair.first, std::move(cloned_data)); } } SupportsUserData::~SupportsUserData() { if (!user_data_.empty()) { DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); } DataMap local_user_data; user_data_.swap(local_user_data); // Now this->user_data_ is empty, and any destructors called transitively from // the destruction of |local_user_data| will see it that way instead of // examining a being-destroyed object. } void SupportsUserData::ClearAllUserData() { DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); user_data_.clear(); } } // namespace base